Beneath a soft blue summer sky with hazy white clouds we are atop the crest of Blue Mountain standing on a grassy overlook looking across a dense thicket of shrubs and then the treetops of the forested mountainside below. We are looking north along the wooded ridgeline of Blue Mountain into Pennsylvania, where the mountain becomes more of a mountain range, throwing out impressive spur ridges. To our left is a small wedge of the vast agricultural Cumberland Valley with farms and small villages. Straight ahead on a small plateau partway down the western slope of blue mountain is a large grassy park: Pen Mar County Park in Maryland on the Pennsylvania border.